Fuel cell cartridge filters and pressure relief

ABSTRACT

Described herein is a portable storage device that stores a hydrogen fuel source. The storage device includes a bladder that contains the hydrogen fuel source and conforms to the volume of the hydrogen fuel source. A housing provides mechanical protection for the bladder. The storage device also includes a connector that interfaces with a mating connector to permit transfer of the fuel source between the bladder and a device that includes the mating connector. The device may be a portable electronics device such as a laptop computer. Refillable hydrogen fuel source storage devices and systems are also described. Hot swappable fuel storage systems described herein allow a portable hydrogen fuel source storage device to be removed from a fuel processor or electronics device it provides the hydrogen fuel source to, without shutting down the receiving device or without compromising hydrogen fuel source provision.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under U.S.C. §120 from co-pending U.S.patent application No. 10/877,766, filed Jun. 25, 2004 and entitled,“PORTABLE FUEL CARTRIDGE FOR FUEL CELLS”, which is incorporated hereinfor all purposes and which claims priority under 35 U.S.C. §119(e) from:a) U.S. Provisional Patent Application No. 60/482,996 filed Jun. 27,2003 and entitled “Fuel cell system startup procedure and self-heatingapparatus”, which is incorporated by reference for all purposes; b) U.S.Provisional Patent Application No. 60/483,415 filed Jun. 27, 2003 andentitled “Refillable Smart Methanol Cartridge for Fuel Cells”, which isincorporated by reference for all purposes; and c) U.S. ProvisionalPatent Application No. 60/483,416 filed Jun. 27, 2003 and entitled “FuelPreheat in Portable Electronics Powered by Fuel Cells”, which isincorporated by reference for all purposes.

BACKGROUND OF THE INVENTION

The present invention relates to fuel cell technology. In particular,the invention relates to portable fuel cell storage devices that store afuel source, allow transportation of the fuel source, and permitcoupling to electronics devices including a fuel processor that convertsthe fuel source to hydrogen.

A fuel cell electrochemically combines hydrogen and oxygen to produceelectrical energy. The ambient air readily supplies oxygen. Hydrogenprovision, however, calls for a working supply. Gaseous hydrogen has alow energy density that reduces its practicality as a portable fuel.Liquid hydrogen, which has a suitable energy density, must be stored atextremely low temperatures and high pressures, making storing andtransporting liquid hydrogen burdensome.

A reformed hydrogen supply processes a fuel source to produce hydrogen.The fuel source acts as a hydrogen carrier. Currently availablehydrocarbon fuel sources include methanol, ethanol, gasoline, propaneand natural gas. Liquid hydrocarbon fuel sources offer high energydensities and the ability to be readily stored and transported. A fuelprocessor reforms the hydrocarbon fuel source to produce hydrogen.

To date, fuel cell evolution has concentrated on large-scaleapplications such as industrial size generators for electrical powerback-up. Consumer electronics devices and other portable electricalpower applications currently rely on lithium ion and similar batterytechnologies. Portable fuel source storage devices that service portableelectronics such as laptop computers would be desirable but are not yetcommercially available.

SUMMARY OF THE INVENTION

The present invention relates to a portable storage device that stores ahydrogen fuel source. The storage device includes a bladder thatcontains the hydrogen fuel source and conforms to the volume of thehydrogen fuel source. A housing provides mechanical protection for thebladder. The storage device also includes a connector that interfaceswith a mating connector to permit transfer of the fuel source betweenthe bladder and a device that includes the mating connector. The devicemay be a portable electronics device such as a laptop computer. Adigital, electrical or mechanical means of identifying and updatinginformation relevant to usage of the storage device may also beemployed.

Refillable hydrogen fuel source storage devices are also provided. Ahydrogen fuel source refiller includes the mating connector and fillsthe storage device with hydrogen fuel source.

In a fuel cell system that receives the hydrogen fuel source from thestorage device, a fuel processor may reform the hydrogen fuel source toproduce hydrogen, and then provides the hydrogen to a fuel cell thatgenerates electricity using the hydrogen.

Hot swappable fuel storage systems described herein allow a portablehydrogen fuel source storage device to be removed from a fuel processoror electronics device it provides the hydrogen fuel source to, withoutshutting down the receiving device or without compromising hydrogen fuelsource provision to the receiving device for a limited time. The hotswappable system comprises a reserve that provides the hydrogen fuelsource to the receiving device. The reserve includes a volume thatstores the hydrogen fuel source when the connector and mating connectorare separated.

In one aspect, the present invention relates to a storage device forstoring a hydrogen fuel source. The storage device comprises a bladderthat contains the hydrogen fuel source and conforms to the volume of thehydrogen fuel source in the bladder. The storage device also comprises ahousing that provides mechanical protection for the bladder. The storagedevice further comprises a connector that interfaces with a matingconnector to permit transfer of the fuel source between the bladder anda device that includes the mating connector. The storage deviceadditionally comprises memory that stores information relevant to usageof the storage device.

In another aspect, the present invention relates to a storage device forstoring a hydrogen fuel source. The storage device comprises a bladderthat contains the hydrogen fuel source and conforms to the volume of thehydrogen fuel source in the bladder. The storage device also comprises ahousing that provides mechanical protection for the bladder. The storagedevice further comprises a connector that interfaces with a matingconnector included in a hydrogen fuel source refiner to permit transferof the hydrogen fuel source from the hydrogen fuel source refiner to thebladder.

In yet another aspect, the present invention relates to a hot swappablefuel storage system. The hot swappable system comprises a hydrogen fuelsource storage device. The storage device includes a) a bladder thatcontains the hydrogen fuel source and conforms to the volume of thehydrogen fuel source in the bladder, b) a housing that providesmechanical protection for the bladder; and c) a connector. The hotswappable system also comprises a mating connector that interfaces withthe connector to permit transfer of the hydrogen fuel source between thestorage device and a device that includes the mating connector. The hotswappable system further comprises a fuel processor that includes areformer configured to receive the hydrogen fuel source from the matingconnector, configured to output hydrogen, and including a catalyst thatfacilitates the production of hydrogen. The hot swappable systemadditionally comprises a hot swappable reserve configured to store thehydrogen fuel source when the connector and mating connector areseparated.

In still another aspect, the present invention relates to system forproviding a refillable hydrogen fuel source storage device. The systemcomprises a hydrogen fuel source storage device. The storage deviceincludes a) a bladder that contains the hydrogen fuel source andconforms to the volume of the hydrogen fuel source in the bladder, b) ahousing that provides mechanical protection for the bladder; and c) aconnector that interfaces with a mating connector to permit transfer ofthe hydrogen fuel source between the bladder and a device that includesthe mating connector. The system also comprises a hydrogen fuel sourcerefiner including the mating connector and configured to providehydrogen fuel source to the storage device when the connector is coupledto the mating connector.

In another aspect, the present invention relates to a fuel cell systemfor producing electrical energy. The fuel cell system comprises ahydrogen fuel source storage device for storing a hydrogen fuel source.The storage device includes a bladder that contains the hydrogen fuelsource and conforms to the volume of the hydrogen fuel source in thebladder. The storage device also includes a housing that providesmechanical protection for the bladder. The storage device furtherincludes a memory that stores information relevant to usage of thestorage device. The storage device additionally includes a connectorthat interfaces with a mating connector to permit transfer of thehydrogen fuel source between the bladder and a device that includes themating connector. The fuel cell system also comprises a fuel processor.The fuel processor includes a reformer configured to receive thehydrogen fuel source from the mating connector, configured to outputhydrogen, and including a catalyst that facilitates the production ofhydrogen. The fuel processor also includes a burner configured toprovide heat to the reformer. The fuel cell system also comprises a fuelcell including a fuel cell stack configured to produce electrical energyusing hydrogen output by the fuel processor.

These and other features and advantages of the present invention will bedescribed in the following description of the invention and associatedfigures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a fuel cell system for producing electrical energyin accordance with one embodiment of the present invention.

FIG. 1B illustrates schematic operation for the fuel cell system of FIG.1A in accordance with a specific embodiment of the present invention.

FIG. 2A shows a simplified hydrogen fuel source storage device inaccordance with one embodiment of the present invention.

FIG. 2B illustrates a cross sectional view of a hydrogen fuel sourcestorage device in accordance with another embodiment of the presentinvention.

FIG. 2C illustrates a bellows configuration used in the storage deviceof FIG. 2B at its maximum volume.

FIG. 2D illustrates a front view of a fuel source storage device inaccordance with one embodiment of the present invention.

FIG. 2E illustrates a front view of a storage device that is compatiblewith the storage device of FIG. 2D in accordance with another embodimentof the present invention.

FIG. 2F illustrates a front view of a storage device that is notcompatible with the storage device of FIG. 2D in accordance with oneembodiment of the present invention.

FIG. 2G illustrates a side view of the storage device of FIG. 2F.

FIG. 3 illustrates of a system for refilling a hydrogen fuel sourcestorage device in accordance with one embodiment of the presentinvention.

FIG. 4 illustrates of a system for producing electrical energy for aportable electronics device in accordance with one embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is described in detail with reference to a fewpreferred embodiments as illustrated in the accompanying drawings. Inthe following description, numerous specific details are set forth inorder to provide a thorough understanding of the present invention. Itwill be apparent, however, to one skilled in the art, that the presentinvention may be practiced without some or all of these specificdetails. In other instances, well known process steps and/or structureshave not been described in detail in order to not unnecessarily obscurethe present invention.

FIG. 1A illustrates a fuel cell system 10 for producing electricalenergy in accordance with one embodiment of the present invention. Fuelcell system 10 comprises storage device 16, fuel processor 15 and fuelcell 20.

Storage device 16 and fuel processor 15 provide hydrogen to fuel cell20. Storage device 16 and fuel processor 15 collectively act as a“reformed” hydrogen supply that processes a hydrogen fuel source 17 toproduce hydrogen. Hydrogen fuel source 17 acts as a carrier for hydrogenand can be processed to separate hydrogen. Hydrogen fuel source 17 mayinclude any hydrogen bearing fuel stream, aliphatic fuel source or otherhydrogen carrier such as ammonia. Currently available hydrocarbon fuelsources 17 suitable for use with the present invention include methanol,ethanol, gasoline, propane, butane and natural gas, for example. Severalhydrocarbon and ammonia products may also produce a suitable fuel source17. Liquid fuel sources 17 offer high energy densities and the abilityto be readily stored and shipped.

Storage device 16 stores fuel source 17, and may comprise a refillableand/or disposable fuel cartridge. A refillable cartridge offers a userinstant recharging. In one embodiment, the cartridge includes acollapsible bladder within a hard plastic case. Storage device 16 isportable and described in further detail below.

A separate fuel pump typically controls fuel source 17 flow from storagedevice 16. If system 10 is load following, then a control system metersfuel source 17 to deliver fuel source 17 to processor 15 at a flow ratedetermined by the required power level output of fuel cell 20.

Fuel processor 15 processes the hydrocarbon fuel source 17 and outputshydrogen. A hydrocarbon fuel processor 15 heats and processes ahydrocarbon fuel source 17 in the presence of a catalyst to producehydrogen. Fuel processor 15 comprises a reformer, which is a catalyticdevice that converts a liquid or gaseous hydrocarbon fuel source 17 intohydrogen and carbon dioxide. As the term is used herein, reformingrefers to the process of producing hydrogen from a fuel source.

Fuel cell 20 electrochemically converts hydrogen and oxygen to water,generating electrical energy and heat in the process. Ambient aircommonly supplies oxygen for fuel cell 20. A pure or direct oxygensource may also be used for oxygen supply. The water often forms as avapor, depending on the temperature of fuel cell 20 components. Theelectrochemical reaction also produces carbon dioxide as a byproduct formany fuel cells.

In one embodiment, fuel cell 20 is a low volume polymer electrolytemembrane (PEM) fuel cell suitable for use with portable applicationssuch as consumer electronics. A polymer electrolyte membrane fuel cellcomprises a membrane electrode assembly 40 that carries out theelectrical energy generating electrochemical reaction. The membraneelectrode assembly 40 includes a hydrogen catalyst, an oxygen catalystand an ion conductive membrane that a) selectively conducts protons andb) electrically isolates the hydrogen catalyst from the oxygen catalyst.A hydrogen gas distribution layer contains the hydrogen catalyst andallows the diffusion of hydrogen therethrough. An oxygen gasdistribution layer contains the oxygen catalyst and allows the diffusionof oxygen and hydrogen protons therethrough. The ion conductive membraneseparates the hydrogen and oxygen gas distribution layers. In chemicalterms, the anode comprises the hydrogen gas distribution layer andhydrogen catalyst, while the cathode comprises the oxygen gasdistribution layer and oxygen catalyst.

A PEM fuel cell often includes a fuel cell stack having a set ofbi-polar plates. A membrane electrode assembly is disposed between twobi-polar plates. Hydrogen distribution 43 occurs via a channel field onone plate while oxygen distribution 45 occurs via a channel field on asecond facing plate. Specifically, a first channel field distributeshydrogen to the hydrogen gas distribution layer, while a second channelfield distributes oxygen to the oxygen gas distribution layer. The term“bi-polar” refers electrically to a bi-polar plate (whether comprised ofone plate or two plates) sandwiched between two membrane electrodeassembly layers. In this case, the bi-polar plate acts as both anegative terminal for one adjacent membrane electrode assembly and apositive terminal for a second adjacent membrane electrode assemblyarranged on the opposite face of the bi-polar plate.

In electrical terms, the anode includes the hydrogen gas distributionlayer, hydrogen catalyst and bi-polar plate. The anode acts as thenegative electrode for fuel cell 20 and conducts electrons that arefreed from hydrogen molecules so that they can be used externally, e.g.,to power an external circuit. In a fuel cell stack, the bi-polar platesare connected in series to add the potential gained in each layer of thestack. In electrical terms, the cathode includes the oxygen gasdistribution layer, oxygen catalyst and bi-polar plate. The cathoderepresents the positive electrode for fuel cell 20 and conducts theelectrons back from the external electrical circuit to the oxygencatalyst, where they can recombine with hydrogen ions and oxygen to formwater.

The hydrogen catalyst separates the hydrogen into protons and electrons.The ion conductive membrane blocks the electrons, and electricallyisolates the chemical anode (hydrogen gas distribution layer andhydrogen catalyst) from the chemical cathode. The ion conductivemembrane also selectively conducts positively charged ions.Electrically, the anode conducts electrons to a load (electrical energyis produced) or battery (energy is stored). Meanwhile, protons movethrough the ion conductive membrane. The protons and used electronssubsequently meet on the cathode side, and combine with oxygen to formwater. The oxygen catalyst in the oxygen gas distribution layerfacilitates this reaction. One common oxygen catalyst comprises platinumpowder very thinly coated onto a carbon paper or cloth. Many designsemploy a rough and porous catalyst to increase surface area of theplatinum exposed to the hydrogen and oxygen.

In one embodiment, fuel cell 20 comprises a set of bi-polar platesformed from a single plate. Each plate includes channel fields onopposite faces of the plate. Since the electrical generation process infuel cell 20 is exothermic, fuel cell 20 may implement a thermalmanagement system to dissipate heat from the fuel cell. Furtherdescription of a fuel cell suitable for use with the present inventionis included in commonly owned co-pending patent application entitled“Micro Fuel Cell Architecture” naming Ian Kaye as inventor and filed onJun. 25, 2004, which is incorporated by reference for all purposes.

While the present invention will mainly be discussed with respect to PEMfuel cells, it is understood that the present invention may be practicedwith other fuel cell architectures. The main difference between fuelcell architectures is the type of ion conductive membrane used. In oneembodiment, fuel cell 20 is phosphoric acid fuel cell that employsliquid phosphoric acid for ion exchange. Solid oxide fuel cells employ ahard, non-porous ceramic compound for ion exchange and may be suitablefor use with the present invention. Generally, any fuel cellarchitecture may benefit from the fuel storage improvements describedherein. Other such fuel cell architectures include direct methanol,alkaline and molten carbonate fuel cells.

Fuel cell 20 generates dc voltage that may be used in a wide variety ofapplications. For example, electrical energy generated by fuel cell 20may be used to power a motor or light. In one embodiment, the presentinvention provides “small” fuel cells that are configured to output lessthan 200 watts of power (net or total). Fuel cells of this size arecommonly referred to as “micro fuel cells” and are well suited for usewith portable electronics devices. In one embodiment, fuel cell 20 isconfigured to generate from about 1 milliwatt to about 200 watts. Inanother embodiment, fuel cell 20 generates from about 3 W to about 20 W.Fuel cell 20 may also be a stand-alone fuel cell, which is a single unitthat produces power as long as it has an a) oxygen and b) hydrogen or ahydrocarbon fuel supply. A stand-alone fuel cell 20 that outputs fromabout 40 W to about 100 W is well suited for use in a laptop computer.

In one embodiment, fuel processor 15 is a steam reformer that only needssteam and the fuel source 17 to produce hydrogen. Several types ofreformers suitable for use in fuel cell system 10 include steamreformers, auto thermal reformers (ATR) or catalytic partial oxidizers(CPOX). ATR and CPOX reformers mix air with the fuel and steam mix. ATRand CPOX systems reform fuels such as methanol, diesel, regular unleadedgasoline and other hydrocarbons. In a specific embodiment, storagedevice 16 provides methanol 17 to fuel processor 15, which reforms themethanol at about 250° C. or less and allows fuel cell system 10 use inapplications where temperature is to be minimized. Further descriptionof a fuel processor suitable for use with the present invention isincluded in commonly owned co-pending patent application entitled“Efficient Micro Fuel Cell Systems and Methods” naming Ian Kaye asinventor and filed on Jun. 25, 2004, which is incorporated by referencefor all purposes.

FIG. 1B illustrates schematic operation for fuel cell system 10 inaccordance with a specific embodiment of the present invention. Asshown, fuel cell system 10 comprises hydrogen fuel source storage device16, hydrogen fuel source 17, fuel processor 15, fuel cell 20, multiplepumps 21 and fans 35, fuel lines and gas lines, and one or more valves23.

Fuel container 16 stores methanol as a hydrogen fuel source 17. Anoutlet 26 of fuel container 16 provides methanol 17 into hydrogen fuelsource line 25. As shown, line 25 divides into two lines: a first line27 that transports methanol 17 to a burner 30 for fuel processor 15 anda second line 29 that transports methanol 17 to reformer 32 in fuelprocessor 15. Lines 25, 27 and 29 may comprise plastic tubing, forexample. Separate pumps 21 a and 21 b are provided for lines 27 and 29,respectively, to pressurize the lines and transmit the fuel source atindependent rates if desired. A model P625 pump as provided by Instechof Plymouth Meeting, PA is suitable to transmit liquid methanol forsystem 10 is suitable in this embodiment. A flow sensor or valve 23situated on line 29 between storage device 16 and fuel processor 15detects and communicates the amount of methanol 17 transfer betweenstorage device 16 and reformer 32. In conjunction with the sensor orvalve 23 and suitable control, such as digital control applied by aprocessor that implements instructions from stored software, pump 21 bregulates methanol 17 provision from storage device 16 to reformer 32.

Fan 35 a delivers oxygen and air from the ambient room through line 31to regenerator 36 of fuel processor 15. Fan 35 b delivers oxygen and airfrom the ambient room through line 33 to regenerator 36 of fuelprocessor 15. In this embodiment, a model AD2005DX-K70 fan as providedby Adda USA of California is suitable to transmit oxygen and air forfuel cell system 10. A fan 37 blows cooling air over fuel cell 20 andits heat transfer appendages 46.

Fuel processor 15 receives methanol 17 from storage device 16 andoutputs hydrogen. Fuel processor 15 comprises burner 30, reformer 32 andboiler 34. Burner 30 includes an inlet that receives methanol 17 fromline 27 and a catalyst that generates heat with methanol presence.Boiler 34 includes an inlet that receives methanol 17 from line 29. Thestructure of boiler 34 permits heat produced in burner 30 to heatmethanol 17 in boiler 34 before reformer 32 receives the methanol 17.Boiler 34 includes an outlet that provides heated methanol 17 toreformer 32. Reformer 32 includes an inlet that receives heated methanol17 from boiler 34. A catalyst in reformer 32 reacts with the methanol 17and produces hydrogen and carbon dioxide. This reaction is slightlyendothermic and draws heat from burner 30. A hydrogen outlet of reformer32 outputs hydrogen to line 39. In one embodiment, fuel processor 15also includes a preferential oxidizer that intercepts reformer 32hydrogen exhaust and decreases the amount of carbon monoxide in theexhaust. The preferential oxidizer employs oxygen from an air inlet tothe preferential oxidizer and a catalyst, such as ruthenium or platinum,that is preferential to carbon monoxide over carbon dioxide.

Fuel processor may also include a dewar 36 that pre-heats air before theair enters burner 30. The dewar also reduces heat loss from fuel cell 20by heating the incoming air before it escapes fuel processor 15. In onesense, dewar acts as a regenerator that uses waist heat in fuelprocessor 15 to increase thermal management and thermal efficiency ofthe fuel processor. Specifically, waist heat from burner 30 may be usedto pre-heat incoming air provided to burner 30 to reduce heat transferto the air in the burner so more heat transfers to reformer 32.

Line 39 transports hydrogen from fuel processor 15 to fuel cell 20.Gaseous delivery lines 31, 33 and 39 may comprise plastic tubing, forexample. A hydrogen flow sensor (not shown) may also be added on line 39to detect and communicate the amount of hydrogen being delivered to fuelcell 20. In conjunction with the hydrogen flow sensor and suitablecontrol, such as digital control applied by a processor that implementsinstructions from stored software, fuel processor 15 regulates hydrogengas provision to fuel cell 20.

Fuel cell 20 includes a hydrogen inlet port that receives hydrogen fromline 39 and delivers it to a hydrogen intake manifold for delivery toone or more bi-polar plates and their hydrogen distribution channels 43.An oxygen inlet port of fuel cell 20 receives oxygen from line 33 anddelivers it to an oxygen intake manifold for delivery to one or morebi-polar plates and their oxygen distribution channels 45. An anodeexhaust manifold collects gases from the hydrogen distribution channels43 and delivers them to an anode exhaust port, which outlets the exhaustgases into the ambient room. A cathode exhaust manifold collects gasesfrom the oxygen distribution channels 45 and delivers them to a cathodeexhaust port.

In addition to the components shown in shown in FIG. 1B, system 10 mayalso include other elements such as electronic controls, additionalpumps and valves, added system sensors, manifolds, heat exchangers andelectrical interconnects useful for carrying out functionality of a fuelcell system 10 that are known to one of skill in the art and omittedherein for sake of brevity.

FIG. 2A shows a simplified hydrogen fuel source storage device 16 inaccordance with one embodiment of the present invention. FIG. 2Billustrates a cross sectional view of a storage device 16 in accordancewith another embodiment of the present invention. Referring initially toFIG. 2A, hydrogen fuel source storage device 16 comprises a bladder 100,housing 102, connector 104 and memory 106.

Bladder 100 contains the hydrogen fuel source 17 and conforms to thevolume of the hydrogen fuel source in the bladder. In one embodiment,bladder 100 comprises a compliant structure that mechanically assumes avolume 115 according to a volume of liquid stored therein. The volume115 is formed by compliant walls 101 of bladder 100, which expand and/oropen when fluid is added to bladder 100, and contract and/or collapsewhen fluid is removed according to the negative pressure developed uponfluid removal. In one embodiment, bladder 100 includes a sac thatchanges size and shape with the volume of liquid contained therein.Plastic, rubber, latex or a metal such as nickel are suitable materialsfor use with the walls 101 of bladder 100. In this case, the walls 101are compliant and change size with a changing liquid volume 115. FIG. 2Billustrates a bellows design for bladder 100 that will be discussed infurther detail below. Plastic walls 101 may also comprise a fireretardant plastic material. One suitable fire retardant plastic materialfor walls 101 is NFPA-701-99 Test 1 Polyethelyne as provided byPlasticare of Orange Park, Fla. In another embodiment, bladder 100comprises a fixed cylinder and a piston that is pushed by a spring andmoves in the cylinder to displace used fuel.

Bladder 100 is characterized by a maximum volume 119 when the bladderfully expands. FIG. 2C illustrates the bellows configuration used in thestorage device of FIG. 2B at its maximum volume 119. In a specificembodiment, maximum volumes for bladder 100 range from about 20milliliters to about 4 liters. Maximum volumes from about 20 millilitersto about 400 milliliters are suitable for many portable electronicsapplications. A maximum volume for bladder 100 of 200 milliliters issuitable for laptop computer usage. Some extended run time systems mayrely on storage devices 16 having 80 liters of maximum volume. Themaximum volume for bladder 100 may differ from the fuel source capacityof storage device 16. In some cases, storage device 16 comprisesmultiple bladders 100 that each contributes a maximum volume thatcumulatively add to a total fuel source capacity for storage device 16.For example, a spare storage device 16 intended for electronics powerback-up may contain two bladders 100 each including 300 milliliters ofhydrogen fuel source 17.

While the present invention primarily refers to the storage of methanolin bladder 100 and storage device 16, it is understood that bladder 100and storage device 16 may contain other hydrocarbon fuel sources such asthose listed above. In addition, bladder 100 may contain a fuel mixture.For example, when the fuel processor 15 fed by storage device 16comprises a steam reformer, bladder 100 may contain a fuel mixture of ahydrocarbon fuel source and water. Hydrocarbon fuel source/water fuelmixtures are often represented as a percentage fuel source in water. Inone embodiment, hydrogen fuel source 17 comprises methanol or ethanolconcentrations in water in the range of 1%-99.9%. Alternatively,hydrogen fuel source 17 may comprise 100% methanol or ethanol. Otherliquid fuels such as butane, propane, gasoline, military grade “JP8”etc. may also be contained in storage device 16 with concentrations inwater from 5-100%. In a specific embodiment, bladder 100 stores 67%methanol by volume.

Housing 102 provides mechanical protection for bladder 100 and any othercomponents of storage device 16 included within housing 102. Housing 102comprises a set of rigid walls 110 that contain bladder 100 and otherinternal components of storage device 16. In one embodiment, allcomponents of storage device 16 are contained within housing 102 saveany portions of connector 104 that protrude out of the housing forinterface with mating connector 140. In another embodiment, connector104 is recessed within housing 102 and housing 102 provides an outershell that substantially defines outer bounds and shape of storagedevice 16. Walls 110 collectively form an outer case or shell forstorage device 16 that mechanically separates components internal tohousing 102 from the external environment. Walls 110 also collectivelyform an interior cavity 112. Interior cavity 112 is a space withinstorage device that contains bladder 100. As described below, interiorcavity 112 may comprises multiple compartments, each of which include aseparate bladder 100.

Rigid walls 110 may comprise a suitably stiff material such as aplastic, metal (e.g., aluminum), polycarbonate, polypropelene, carbonfiber matrix, carbon composite material, etc. Rigid walls 110 may alsobe formed from a fire retardant material such as a fire retardantplastic material. One suitable fire retardant plastic material for walls110 is 8-12% weight, JLS-MC mixed with PA66 Polyamide as provided by JLSChemical of Pomona, Calif. Rigid walls 110 may be designed according tocriteria for construction of thin walled pressure vessels. Such criteriaare known to those of skill in the art. In this case, walls 110 andhousing 102 may be designed to withstand a maximum pressure withininternal cavity 112 or for bladder 100.

Housing 102 may include an elliptical (including circular) shape, arectangular shape with chamfered corners, or other substantiallyconsistent profile or shape in a given direction. FIGS. 2D-2F illustratesome suitable housing 102 shapes. For the embodiment of FIG. 2B, housing102 includes a substantially consistent shape in a direction 125 thatextends normally away from a tube 107 in connector 104. In oneembodiment, housing 102 comprises a transparent section or clear windowto allow for visual fuel gauging.

In one embodiment, housing 102 is integrally formed to preventdisassembly of housing 102. In this case, walls 110 may be permanentlybonded or extruded from a common material in one piece such that accessinto housing 102 is only gained through destruction of walls 110 andhousing 102.

Connector 104 interfaces with a mating connector 140 (see FIG. 2B)included in an external device. Together, connector 104 and matingconnector 140 permit transfer of fuel source 17 between bladder 100 andthe external device. When mating connector 140 is included in fuelprocessor 15 or a device that includes fuel processor 15, connector 104and mating connector 140 interface to permit transfer of fuel source 17from storage device 16 to the fuel processor 15. Alternatively, whenmating connector 140 is included in a hydrogen fuel source refiller,connector 104 and mating connector 140 interface to permit transfer offuel source 17 from the refiner to storage device 16. Interface betweenconnector 104 and mating connector 140 may comprise any relationship andmating structures that permit fluid communication between the twoconnectors. Connector 104 and/or mating connector 140 may also includemechanical coupling to secure the interface, such as latching elementsthat bind connector 104 and mating connector 140 together untilphysically released. Connector 104 and mating connector 140 may alsoeach include electrical leads that contact when the connectors areattached to enable electrical and digital communication.

Connector 104 and mating connector 140 each comprise a geometry that atleast partially matches geometry of the other. Exemplary connector 104and mating connector 140 geometries are described below with respect toFIGS. 2D-2G.

In one embodiment, connector 104 incorporates a quick disconnect thatpermits storage device 16 to be readily removed by pulling on housing102. This separates connector 104 and mating connector 140 and detachesany electrical links and plumbing responsible for fluid communicationbetween storage device 16 and the device including mating connector 140.A second storage device 16 with a quick disconnect connector 104 maythen be readily inserted back into mating connector 140. The quickdisconnect thus allows rapid replacement of storage device 16 withanother storage device 16 when fuel source volume levels are low. Thequick disconnect connector 104 includes one port or multiple portsaccording to the plumbing needs of storage device 16 (e.g., fuelprovision and a scrubbing bed). A quick disconnect connector 104 mayalso include other features to control removal requirements such as twohanded operation or a high force actuator. Commercially available quickdisconnect connectors are available from a variety of vendors. Onesuitable quick disconnect connector is model number QDC101 as providedby Beswick of Greenland, NH. As will be described in further detailbelow, storage device 16 may also include a hot swappable capabilitythat improves quick disconnect usage for connector 104 and matingconnector 140.

Connector 104 and mating connector 140 may provide an automatic shutoffcapability when device 16 is removed from system 202. In this case, eachonly open when connected to the other and when device 16 interfaces withdevice 202. In one embodiment, device 16 comprises a small sponge orswab located on or near connector 104 to collect any fuel leakage duringdevice connection or disconnect.

In one embodiment, one of connector 104 and mating connector 140includes a ‘male’ designation and configuration while the other includesa ‘female’ designation and configuration. The male configurationincludes portions of the connector that protrude, such as one or morepins or electrical leads. The female configuration includes portions ofthe connector that receive the male portions, such as holes electricallylined to receive the male portion and facilitate electricalcommunication. As shown in FIG. 2G, connector 104 on storage device 16includes a female configuration that recesses within housing 102. Sinceit is recessed, connector 104 cannot be knocked off during roughhandling. Mating connector 140 is configured on a side portion of an OEMdevice (i.e., a laptop computer). As will be described in further detailbelow, mating connector 140 is also included in refilling hardware thatrefills storage device 16 with fuel source 17.

Memory 106 stores information relevant to usage of storage device 16.Memory 106 may comprise a mechanical, electrical and/or digitalmechanism for information storage. In one embodiment, memory 106comprises a digital memory source that permits an external controller toread and write from the digital memory. In another embodiment, memory106 includes a mechanical device. One suitable mechanical devicecomprises “break-off” pins 158 (see FIG. 2D). Other forms of mechanicalmemory 106 may comprise discs or rods which are removed or otherwisemanipulated every time a storage device 16 is refilled. For theembodiment shown in FIG. 2D, memory 106 is external to housing 102 andcomprises a visible identification tag that uniquely identifies storagedevice 16. Various types of external identification tags are known inthe art and may be used with this invention. Two examples ofidentification identifier tags include magnetic recording devices andoptical bar codes.

In one embodiment, storage device 16 is considered “smart” since memory106 stores information related to the performance, status and abilitiesof storage device 16. A digital memory allows an external controller orlogic to read and write information relevant to usage of the storagedevice to memory 106. Reading from a digital memory 106 allows receptionand assessment of information in memory 106 to improve usage of storagedevice 16. For example, a computer that receives storage device 16 mayinform a user that the storage device 16 is empty or how much fuel isleft (or how much time on the system is available based on its powerconsumption and the amount of fuel remaining). Writing to a digitalmemory 106 allows information in memory 106 to be updated according tostorage device 16 usage. Thus, if a user nearly depletes fuel source 17in storage device 16 while powering a computer, the next user may beinformed after the first computer writes an updated amount of fuelsource 17 remaining in storage device 16 into memory 106.

Storage device 16 specifications stored in memory 106 generally do notchange with device 16 usage and may comprise a) a fuel type stored inthe storage device when device 16 is dedicated to service a particularhydrocarbon fuel source 17, b) a model number for storage device 16, c)an identification signature for the manufacturer of storage device 16,d) manufacture date, and e) a volume capacity for bladder 100 or storagedevice 16. The model number of device 16 allows it to be distinguishedfrom a number of similar devices.

Transient information stored in memory 106 that changes according to thestatus and usage of storage device 16 may comprise a) hydrogen fuelmixture information, b) a number of refills provided to storage device16 when device 16 is configured for re-usable service, c) the lastrefill date, d) the refilling service provider that refilled storagedevice 16 when the device is configured for re-usable service, e) usagehistory according to a storage device identification, and f) a currentvolume for the storage device.

Referring now to FIG. 2B, storage device 16 comprises a bladder 100 witha collapsible bellows configuration 126, housing 102, connector 104,memory 106, air vent 132, filter 134, pressure relief valve 136, fireretardant foam 138, mechanical shield 142, and fuel source filter 144.Connector 104 comprises tube 107 and female bay 117. Storage device 16connects to a laptop computer 202, which includes mating connector 140.Mating connector 140 comprises tube 109, reserve volume 302 and malehousing 113.

Mating connector 140 interfaces with connector 104 to permit transfer ofhydrogen fuel source 17 from storage device 16 to laptop computer 202.In one embodiment, storage device 16 resembles a battery-sized cartridgeincluding a female connector 104 that receives a male mating connector140. Male housing 113 of mating connector 140 fits snugly into a femalebay 117 of connector 104 (see FIG. 2G for side view of a bay 117). Thefit provides mechanical support for the interface between matingconnector 140 and connector 104. Distal end of tube 107 in storagedevice 16 and a distal end of tube 109 in mating connector 140 alignwhen connector 104 and mating connector 140 join. In a specificembodiment, tube 109 comprises a pointed end that pierces into tube 107and tube 109 comprises a diameter that snugly fits into tube 107 whenconnector 104 and mating connector 140 are attached.

When mating connector 140 and connector 104 are joined as shown, a pumprun by a fuel cell system 10 within laptop computer 202 draws fluid frombladder 100 into the fuel cell system 10. More specifically, fuel source17 travels from bladder 100, through tube 107 in connector 104, into andthrough tube 109 in mating connector 140, and through tube 109 in laptopcomputer 202 to a fuel processor 15 included therein.

Connector 104 and mating connector 140 may also include electricalconnectivity for digital communication between memory 106 and aprocessor or controller (see FIG. 4) on laptop computer 202. FIG. 2Fillustrates female electrical slots 155 on connector 104 b. A matingconnector 140 for connector 104 b then includes male leads (not shown)that fit into slots 155 for electrical communication between laptopcomputer 202 and storage device 16.

For the embodiment of FIG. 2B, bladder 100 comprises a collapsiblebellows design 126. One end 127 a of bellows 126 attaches and opens totube 107, while the opposite end 127 b is free to move in direction 125.When bladder 100 fills with fuel source 17, free end 127 b moves indirection 125 and bellows 126 expands and increases in volume. Whenbladder 100 loses fuel source 17, free end 127 b moves opposite todirection 125 and bellows 126 collapses and decreases in volume. Freeend 127 b and bladder 100 thus compresses towards the location wherefuel source 17 is outlet and where negative pressure is created tocontract or collapse bellows 126 (tube 107 and connector 104 in thiscase). FIG. 2C illustrates a bellows configuration 126 at its maximumvolume. As shown in FIG. 2B, bladder 100 is less than half full of fuelsource 17 and assumes less than half the space in internal cavity 112.Bellows 126 comprises collapsible rings 128 that fold as bellows 126expands (the angle of each ring 128 opens) and as bellows 126 collapse(the angle of each ring 128 closes). Bellows 126 may comprise plastic orNickel, for example. Bellows 126 may be custom molded or electroformed.Similarly designed bellows are used to protect tubular warp in machinetools, for example. Servometer Corp. of New Jersey provides severalsuitable commercially available nickel bellows.

Storage device 16 includes an air vent 132 in housing 102 that allowsair to enter and exit in internal cavity 112 within housing 102 asbladder 100 changes in volume. Air vent 132 comprises one or more holesor apertures in a wall 110 of housing 102. In operation, as fuel source17 is consumed and drawn from storage device 16, bladder 100 collapsesand creates a negative pressure in internal cavity 112 outside ofbladder 100. Based on this negative pressure caused by a decreasingvolume of bladder 100 (or increasing volume of internal cavity 112outside bladder 100), air enters through air vent 132 into internalcavity 112 and displaces the decreasing volume of bladder 100. Thisprevents the pressure of fuel source 17 in bladder 100 from decreasingand affecting the ability of storage device 16 to provide fuel source 17at a substantially constant pressure. When filling storage device 16,positive pressure caused by an increasing volume of fuel source 17 andbladder 100 causes air to exit through air vent 132. Since walls ofbladder 100 separate fuel source 17 within bladder 100 from air ininternal cavity 112, air in cavity 112 does not enter bladder 100 or mixwith fuel source 17.

A filter 134 spans the cross section of air vent 132 and intercepts airpassing through air vent 132. In one embodiment, filter 134 comprises ahydrophobic and gas permeable filter that prevents foreign materialsfrom entering storage device 16. Materials blocked by filter 134 mayinclude liquids and particles such as undesirable oils and abrasivesthat may affect storage device 16 performance. The hydrophobic filteralso prevents fuel source 17 from escaping housing 102 in the event thatbladder 100 develops a leak. Filter 134 may comprise micro porous Teflonor another micro porous material such as Teflon coated paper. A sinteredmetal filter, for example one with a 3 micron pore size, may also beused. One suitable filter 134 includes micro porous “Gore Tex” Teflon asprovided by WL Gore Associates of Elkton, Md.

Mechanical shield 142 spans and covers air vent 132 and prevents foreignbodies from entering housing 102 through air vent 132 and damagingbladder 100. In one embodiment, air vent 132 is recessed into a wall 110such that mechanical shield 142 is flush with the outer surface ofhousing 102. As shown, filter 134 is located internal to shield 142 suchthat shield 142 mechanically protects filter 134. In one embodiment,mechanical shield 142 includes a flame suppressor or a suitable means offlame suppression. The mechanical shield 142 then prevents flamepropagation into or out from interior cavity 112. One suitablemechanical shield 142 includes cut to size 180×180 mesh stainless steelscreen as provided by McNichols of Tampa, Fla.

Pressure relief valve 136 limits pressure in storage device 16. Morespecifically, pressure relief valve 136 releases fuel source 17 frombladder 100 when the pressure within bladder 100 reaches a thresholdpressure. The threshold pressure refers to a pressure for bladder 100that represents the upper limit of operational pressure for fuel source17 use in storage device 16. Threshold pressures from about 5 psig toabout 25 psig are suitable for some fuel sources 17 and storage devices16. A threshold pressure of about 15 psig is suitable in many cases.Other suitable threshold pressures may relate to the boiling point ofthe fuel source 17, which ranges from about 2 Atm to about 10 Atm. Thus,if temperature for storage device 16 rises above the boiling point offuel source 17, the threshold pressure is reached and pressure reliefvalve 136 releases fuel source 17 from bladder 100. During normaloperation and storage, the partial pressure of fuel source 17 in bladder100 is less than the threshold pressure and pressure relief valve 136 isnot used. In the event that pressure of fuel source 17 in bladder 100rises above the threshold pressure, pressure relief valve 136 releasesfuel source 17 from bladder 100, thereby limiting the pressure withinbladder 100.

In a specific embodiment, pressure relief valve 136 comprises a sprungdiaphragm mechanism. The sprung diaphragm includes a diaphragm and aspring that attaches to the diaphragm. Pressure in bladder 100 pushesthe diaphragm outward against the spring force. At the thresholdpressure, the diaphragm opens a port—a small hole that opens outside ofhousing 102—to permit the release of fuel source 17 from bladder 100.Spring selection permits a designer to control the threshold pressure atwhich the port opens and fuel source 17 escapes. In another specificembodiment, pressure relief valve 136 comprises a burst disk mechanismthat includes a thin diaphragm. The diaphragm breaks outward whenpressure in bladder 100 rises above the threshold pressure. Thediaphragm break and the resultant opening releases fuel source 17 frombladder 100. For either design, the port or opening may be configured todirect venting fuel vapors away from storage device 16 and into aventilated area when installed in an electronics or OEM device.

A fuel source filter 144 intercepts fuel source 17 as it leaves bladder100 and before it leaves connector 104. As shown, filter 144 spans anentrance to tube 107 from bladder 100. Fuel source filter 144 removesany contaminants or chemicals added to fuel source 17 for storage inbladder 100 and device 16. In one embodiment, fuel source 17 comprisesan odorant 150, a bitterant 152 and/or a colorant 154 mixed therein. Iffuel source 17 comprises an odorless liquid, odorant 150 providesolfactory stimulus to inform a person that fuel source 17 has escapedbladder 100 and storage device 16 via a path other than through tube 107and filter 144. Two suitable odorants 150 includes trimethyl amine at1-10 ppm in methanol and ethyl mercaptan at 1-7 ppm weight in methanol.Fuel source filter 144 removes odorant 150 from fuel source 17 when thefuel source leaves bladder 100 through tube 107.

If fuel source 17 comprises a colorless liquid, colorant 154 providesvisual stimulus to inform a person that fuel source 17 has leaked orescaped from bladder 100 via a path other than through tube 107 andfilter 144. Suitable colorants 154 include acid blue 9 at 1 ppm, table5-4 food dye, and bright green/blue erioglaicine disodium salt asprovided by Dudley Chemical Corp of Lakewood, N.J. Fuel source filter144 removes colorant 154 from hydrogen fuel source 17 when the fuelsource leaves bladder 100 through tube 107.

If fuel source 17 comprises liquid with no taste, a bitterant 152 may beadded to provide taste stimulus that informs a person that fuel source17 has escaped bladder 100 via a path other than through tube 107 andfilter 144. One suitable bitterant 152 includes Denatonium Benzoate at1-50 ppm (20-50 ppm is adversely bitter) as provided by Bitrex ofEdinburgh, UK. Fuel source filter 144 removes bitterant 152 fromhydrogen fuel source 17 when fuel source 17 leaves bladder 100 throughtube 107. One suitable filter 144 for removing odorant 150, bitterant152 and/or colorant 154 includes an ultra-pure polyethersulfonemembrane. Another suitable filter 144 for removing odorant 150,bitterant 152 and/or colorant 154 from fuel source 17 includes 0.1Advantage PS C-7012 filter as provided by Parker Hanafin Corp.

A fire retardant foam 138 is disposed in bladder 100. Foam 138 iscompliant and conforms in size to the size of bladder 100. Thus, asbladder 100 collapses, foam 138 compresses. In one embodiment, foam 138acts as a wicking foam that directs some flame behavior in storagedevice 16. One suitable foam 138 is polyurethane mil Spec Mil-B-83054 asprovided by Foamex of Lindwood, Pa.

In one embodiment, memory 106 comprises a wireless identification (ID)tag. This allows memory 106 to communicate with an external device, suchas hydrogen fuel source refiner 162 described in FIG. 3. In this case,the external device includes an interrogator that probes memory 106 viawireless communication when storage device 16 is in range of theinterrogator. The interrogator may include any hardware for performingthis function such as a computer, transceiver and interrogator antenna.Coupling between the interrogator and storage device 16 may occur viaradio frequency (RF) or microwave frequency radiation. When probed bythe interrogator, storage device 16 replies with its identification (asstored in a digital or electrical memory 106) and any other informationstored in memory 106, such as the status of any sensors used in storagedevice 16 to monitor health of the device and sensors that detect thevolume of fuel source in bladder 100. The storage device 16identification provides a means for automated logging of datacorresponding to the status of storage device 16. The identificationalso facilitates inventory logging of information for numerous storagedevices 16.

In one embodiment, the interrogator provides power to storage device 16.The power is transmitted by RF waves, for example, and received by arectifier in storage device 16 that rectifies the signal, therebyproviding sufficient DC power to operate any circuitry of storage device16. A transponder included in storage device 16 responds to a wirelessstimulus. The transponder transmits signals when actuated by a signalfrom an external interrogator. In some cases, the transponder includesan amplifier for increasing the strength of a received incident signal,a modulator for modifying the signal with information stored by memory106, and an antenna or antennas for receiving and transmitting signals.

Wireless ID tags are commercially well known and there exists numerousmanufacturers that currently offer a wide selection of RFID tags. Thesetags are either passive (typically operating near 125 khz) or active(often operating near 2.45 GHz). Major manufacturers include TexasInstruments of Dallas, Tex. and Motorola of San Jose, Calif. or AlienTechnologies of San Jose, Calif. Products are available for inventorycontrol, product labeling, etc. For example, storage device 16 may use acommercial RFID tag, such as a 125-khz tag supplied by Texas Instrumentsof Dallas, Tex., which includes a microchip for memory 106 and inductorfor wireless communication.

Storage device 16 may also comprise a sensor that monitors a conditionrelated to the health or functioning of storage device 16. In oneembodiment, the sensor comprises a wire 156 that runs about an insidesurface of housing 102 or is formed within a wall 110 housing 102 (seeFIG. 2C). An electrical state or performance of wire 156 provides anindication of the health of housing 102. Mechanical damage, cracking orstructural compromise of housing 102 affects wire 156—mechanically andelectrically. More specifically, when wire 156 breaks, stretches orloses contact due to mechanical changes housing 102, an electricalsignal sent through wire 156 changes. The according change may be readand assessed. Thus, a break in wire 156 may be read by non-transmittanceof a signal. Changes in electrical resistance of wire 156 may alsoprovide an indication of health. In one embodiment, the sensor relies onexternal (e.g., RFID) probing to assess the state of wire 156 and healthof housing 102. In this case, the interrogator powers memory 106 to testthe resistance of wire 156. The RFID memory 106 then responds with asignal indicative of the status of wire 156. Although the sensor isshown as a single wire 156, it is understood that more complex designsmay comprise filament networks that extend two dimensionally throughouthousing 102. Each filament may then be probed for its electrical status,e.g., resistance to provide a meshed status check of integrity andhealth of housing 102 and storage device 16.

FIG. 2D illustrates a front view of fuel source storage device 16 a inaccordance with one embodiment of the present invention. FIG. 2Eillustrates a front view of a storage device 16 b that is partiallycompatible with storage device 16 a. FIG. 2F illustrates a front view ofa storage device 16 c that is not compatible with storage device 16 a.FIG. 2G illustrates a side view of a storage device 16 c.

Connector 104 and/or mating connector 140 may include a “keyed”configuration that provides interface selectivity. For example,connector 104 may comprise a configuration unique to a particularhydrogen fuel source (e.g., methanol). In this case, mating connector140 offers an exclusive interface that only receives a connector 104 fora methanol based storage device 16. This keying system prevents thewrong fuel type from being installed in a device that cannot accept thatfuel, e.g., gasoline bums at a higher temperature and may not besuitable for use in all methanol fuel processors. This keying systemalso prevents storage device 16 from being refilled with the wronghydrogen fuel source 17.

For example, storage device 16 a of FIG. 2D includes a circularconnector 104 a that interfaces with a circular mating connector (notshown). Similarly, storage device 16 b of FIG. 2E includes a circularconnector 104 a of the same dimensions that interfaces with the samecircular mating connector as that employed for connector 104 a. Thestorage device 16 c of FIG. 2F includes a rectangular connector 104 bthat would not interface with the same circular mating connector.Circular connectors 104 a may be used for methanol fuel mixtures ofdifferent blends for example, while rectangular connector 104 b is usedfor ethanol.

The keyed configuration of connector also allows for variation of one ofconnector 104 or mating connector 140, while the other remains constant.This controlled variability has numerous commercial applications. In onecommercial system, connector 104 may change slightly while matingconnector 140 remains constant. A common mating connector 140 mayreceive different storage devices 16 that share a connector 104 aconfiguration. The different storage devices 16 may be produced bydifferent manufacturers and may include varying volumes or other storagedevice 16 features. This permits competition for the provision ofstorage devices 16 but standardization of their interface. In anothercommercial application, an electronics device manufacturer such as Dellspecifies a custom mating connector 140 configuration (e.g., a circularconfiguration used in their laptop computers and other electronicsdevices). All storage devices 16 that service these electronics devicesmust then include a connector 104 that matches Dell's custom matingconnector 140 configuration. The electronics device manufacturer maythen control who manufacturers storage devices 16 and connectors 104 foruse with their electronics devices. Keyed connectors 104 a for oneelectronics device manufacturer may also be designed to not fit a matingconnector 140 for another computer manufacturer, e.g., Apple employs arectangular configuration 104 b.

Custom connector 104 and mating connector 140 configurations may varybased on geometry, dimensions, depth and size for example. A connector104 or mating connector 140 may also include one or more features 149that distinguish a custom connector or mating connector. As shown inFIG. 2E, feature 149 is a tab that extends into the female bay 117 ofconnector and mechanically distinguishes storage device 16 b fromstorage device 16 a.

Connector 104/mating connector 140 configuration selectivity may also beimplemented to distinguish developing technology in fuel cell system 10or storage device 16. By changing mating connector 140 to receive onlycertain connectors 104, the present invention permits continuingdevelopment of fuel cell system 10 or storage device 16 and ensuresrejection of previous storage device 16 models that are no longersuitable. For example, storage device 16 b may represent a newer versionof storage device 16 a that is mechanically distinguished by feature149. An electronics device that receives storage devices 16 may includea mating connector 140 that mechanically rejects storage device 16 abased omission of feature 149. Memory 106 may also be digitally read toindicate incompatibility.

The keyed configurations shown in FIGS. 2D-2F may also be implementedfor particular fuel source 17 types. For example, storage device 16 aand connector 104 a may designate a methanol fuel mixture “A%”, whilestorage device 16 b and feature 149 designate a methanol fuel mixture“B%” and storage device 16 c and connector 104 b designates an ethanolfuel mixture.

Storage devices 16 a also comprise “break-off” pins 158 that form amechanical memory 106. Pins 158 indicate the number of refills for eachstorage device 16. Each time storage device 16 is refilled, the refinerbreaks a pin 158. When all the pins have been removed, a matingconnector to connector 104 will not accept storage device 16. Pins 158may comprise plastic and be molded into the cartridge housing 102 or toconnector 104.

In one embodiment, storage device 16 is intended for disposable use. Inthis case, a user purchases a storage device 16 with a full complementof methanol and disposes of storage device 16 after it is emptied. Inanother embodiment, storage device 16 is intended for reusable use. Areusable storage device 16 provides less waste. In this case, storagedevice 16 is refilled by a hydrogen fuel source refiller.

FIG. 3 Illustrates a system 160 for providing a refillable hydrogen fuelsource storage device 16 in accordance with one embodiment of thepresent invention. System 160 comprises storage device 16 and a hydrogenfuel source refiner 162.

Hydrogen fuel source refiller 160 includes mating connector 140 and isconfigured to provide hydrogen fuel source 17 to storage device 16 whenthe connector 104 is coupled to mating connector 140. Connector 104 andmating connector 140 interface to permit transfer of fuel source 17 fromrefiner 160 to storage device 16. Refiller 160 comprises a fuel reservetank 164 that stores hydrogen fuel source 17. Tank is suitably size torefuel numerous storage devices 16. A pump 166 receives control signalsfrom a refiner controller 168 that controls functioning of refiner 160based on stored commands in refiner memory 170. Refiller memory 170 mayalso include a database that stores information for each storage device16 serviced by refiner 160.

A line 172 transports fuel source 17 from tank 164 to storage device 16.More specifically, pump 166 moves fluid fuel source 17 from tank 164through tube 109 in mating connector 140, into and through tube 107 inconnector 104, and into bladder 100 for storage therein. Althoughrefiner 160 is shown refilling a single storage device 16, it isunderstood that refiller 160 may comprise multiple “bays” that eachinclude a mating connector 140 and plumbing to refill a single storagedevice 16. Refiller 160 may also include multiple tanks 164 thatprovided different fuel sources 17, such as different fuel sources(e.g., methanol or ethanol) or different fuel mixtures.

Controller 168 also communicates with memory 106 via line 174, whichtravels from controller 168, through electrical connectivity provided byconnector 104 and mating connector 140 and to memory 106. Controller 168may also communicate with memory 106 via wireless means as describedabove if controller 168 and memory 106 both include such capability.Refiller 160 includes an interrogator 176 to communicate wirelessly witha storage device 16. Interrogator 176 comprises a transceiver andantenna based on the communication frequency employed.

Controller 168 reads from and writes to memory 106. Controller 168 mayread and store the usage history of a digital memory 106. When storagedevice 16 includes a mechanical memory such as the break-off pins 158described above, refiner 162 checks if there are any pins 158 remaining(either mechanically or electronically). If all the pins have beenremoved, refiner 162 does not accept storage device 16. Controller 168may also check the status of any sensors on storage device 16 used tomonitor health of the device 16, such as an RDIF sensor that detectshousing integrity. This helps a re-filling services provider determineif storage device 16 can be simply be refilled, or if it needs torefurbished as well. Via controller 168 and stored logic that dictatesresponses to information read from memory 106, refiner 162 is thusconfigured to detect a defect in storage device 16 and not transferhydrogen fuel source 17 to storage device 16 when a predetermined memoryelement is present. Memory elements may include use of a pressure reliefvalve or information related to the status of any sensors on storagedevice 16.

Controller 168 may also write into memory 106 information such as: thehydrogen fuel mixture information stored therein, an updated number ofrefills provided to storage device 16, the refill date, the refillingservice provider, and a volume for the storage device. When storagedevice 16 includes a mechanical memory such as the break-off pins 158described above, refiner 162 breaks a pin 158 upon refill completion.

Refillable system 160 allows distribution of the hydrogen fuel source 17to be handled flexibly. One approach is to distribute refillable storagedevices 16 similar to the distribution of batteries. A consumerpurchases a desired storage device 16 at a retail outlet, such as adepartment store, super market, airport kiosk or drug store etc. Storagedevice 16 selection may vary based on fuel source 17 capacity, fuelsource 17 type or other features such as connectivity and smartfeatures. Spent storage devices 16 may be dropped off at the any of theabove locations for reuse, and shipped to a refilling services providerfor refurbishment and refill.

When storage device 16 comprises a hydrogen fuel cleaning system,refiner 162 may also rejuvenate or check for replacement of the cleaningsystem. For the scrubbing bed as described below with respect to filter220, refiner 162 rejuvenates the cleaning system by forcing hydrogenthrough the bed (e.g., using hydrogen in tank 164). The scrubbing bedfilter 220 may also be replaced with a new bed when the storage device16 is refilled.

Refilling system 160 allows a hydrogen fuel source 17 refilling providerto control refilling of storage devices 16. Connectors 104 that requirespecific parts on mating connector 140 to complete interface and permitfluid transfer into storage device 16 also prevent free tampering andaddition of fluids to storage device 16. Refilling system 160 alsoprovides a business model for distribution of storage devices 16.Refilling system 160 also permits the hydrogen fuel source 17 refillingprovider to certify fuel blends, monitor the number of refills for aparticular storage device 16, and validate storage device 16 forconsumer or manufacturer confidence.

FIG. 4 shows a schematic illustration of a system 200 for producingelectrical energy for a portable electronics device in accordance withone embodiment of the present invention. System 200 comprises fuelprocessor 15 and fuel cell 20 included within an electronics device 202and a hydrogen fuel source storage device 16 coupled to electronicsdevice 202 via connector 104 and mating connector 140. Electronicsdevice 202 may comprise any portable or stationary electronics device orpower application that relies on a fuel cell to generate electricalenergy.

In one embodiment, fuel processor 15 and fuel cell 20 are incorporatedinto electronics device 202 (within its volume and outer housing) as anintegral module, and storage device 16 is removable allowing for instantrecharging. Fuel cell powered laptop computers 202 may comprise slightlymodified existing products, with fuel processor 15 and fuel cell 20 andrelated system components fitted generally into the space provided for abattery pack. Mating connector 140 is included in this allocated spacefor connection to storage device 16. Storage device 16 mechanicallyinterfaces with electronics device 202. In one embodiment, connectors104 and 140 provide sufficient mechanical force to maintain positionbetween the storage device 16 and electronics device 202. In anotherembodiment, electronics device 202 includes a mechanical slot thatstorage device 16 fits and slides into. In one embodiment, an externalcartridge-mounting bracket is provided to allow for larger storagedevices 16 to be used.

When connector 104 and mating connector 140 interface, fuel cell systemcontroller 214 digitally communicates with memory 106 using link 217 forbi-directional communication therebetween. In another embodiment,controller 214 uses a wireless interrogator to communicate with an RFIDantennae and memory 106 included in storage device 16. Controller 214may read any information stored in memory 106 such as a fuel type storedin the storage device 16, a model number for storage device 16, a volumecapacity for bladder 100 or storage device 16, a number of refillsprovided to storage device 16, the last refill date, the refillingservice provider, and a current volume for the storage device. In onecommercial application, different bladder 100 volumes and storage device16 configurations are offered based on different laptop computermanufacturers and models for a particular manufacturer. The volume maybe configured to meet a specific run time requirement for a particularlaptop model, for example. In this case, controller 214 estimates theremaining power in storage device 16 by comparing the fuel source 17level since last use or refill against a consumption rate for aparticular laptop computer.

Controller 214 may also write transient information to memory 106, suchas an updated volume for the storage device. The controller 214communicates with a main controller 210 for computer 202 and computermemory 218 via communications bus 212. Computer memory 218 may storeinstructions for the control of fuel system 10 such as read and writeprotocol and instructions for communication with a digital memory 106.

System 200 also comprises a hydrogen fuel cleaning system. As shown,storage device 16 comprises a filter 220 in fluidic communication withhydrogen 224 output by fuel processor 15. Filter 220 removescontaminants from the hydrogen 224 stream (or reformate) before receiptby fuel cell 20. The reformate often includes hydrogen, carbon dioxide,carbon monoxide and other small particulates. Filter 220 may removecarbon monoxide, un-converted methanol vapor and/or hydrogen sulfide(among others). As shown, line 226 routes reformate 224 output by ahydrogen outlet of fuel processor 15, back through mating connector 140and connector 104, into storage device 16 and through filter 220, backout of in storage device 16 and to an anode inlet of fuel cell 20. In aspecific embodiment, filter 220 comprises a carbon monoxide scrubbingcatalyst or absorbent arranged in a bed that hydrogen 224 stream passesthrough. The bed is filled with a material, such as activated carbon,potassium permanganate or cupric chloride (CuCl₂). The catalyst orabsorbent absorbs CO, methanol vapor or H₂S. As described above, thescrubbing bed may be rejuvenated by passing hydrogen through the bedwhen the storage device 16 is refilled. Or the scrubbing bed may bereplaced with a new bed when the storage device 16 is refilled. Filter220 simplifies chemical management for fuel processor 15 and increasesthe performance of fuel cell 20. Filter 220 also reduces poisoning ofthe fuel cell 20 catalysts with un-converted methanol vapors, bytrapping the vapors prior to the hydrogen 224 stream entering fuel cell20. In another embodiment, a line routes unused hydrogen from fuel cell20 in the anode exhaust to fuel processor 15 to further increaseefficiency of the fuel cell system in device 202. Further discussion offuel cell systems suitable for use with the present invention aredescribed in commonly owned co-pending patent application entitled“Micro Fuel Cell Architecture” naming Ian Kaye as inventor and filed onJun. 25, 2004, which is incorporated by reference for all purposes.

Power management 216 controls power provision by fuel cell system 10 andelectrochemical battery 222. Thus, power management 216 may informcontroller 214 how much power is needed for laptop computer 202operation and controller 214 responds by sending signals to fuel cell20, fuel processor 15 and a pump that draws fuel from storage device 16to alter fuel cell power production accordingly. If fuel cell system 10runs out of fuel source 17, then power management 216 switches toelectrical power provision from battery 222.

A spare storage device 16 d is included in system 200. Storage device 16d shares a connector 104 with storage device 16 a (currently pluggedin). Storage device 16 d comprises a dual internal compartment 112 a and112 b configuration internal to housing 102 d divided by internal wall10 d. Internal compartment 112 a includes a first bladder 100 b whileinternal compartment 112 b includes a second bladder 100 b. The dualbladder design of storage device 16 d provides extended power back upfor system 200.

System 200 may also be configured for “hot swappable” capability. As theterm is used herein, hot swapping of storage device 16 refers toremoving storage device 16 from a fuel processor or electronics deviceit provides hydrogen fuel source 17 to, without shutting down thereceiving device or without compromising hydrogen fuel source provisionto the receiving device for a limited time. A hot swappable systemimplies fuel source provision when connector 104 and mating connector140 are separated. Referring back to FIG. 2A, electronics device 202comprises a reserve volume 302 that is configured to store the hydrogenfuel source 17 when connector 104 and mating connector 140 areseparated.

The time that a receiving fuel processor or electronics device may beoperated for while connector 104 and mating connector 140 are separatedrelates to the amount of fuel in reserve volume 302 and the rate atwhich the fuel processor or electronics device uses fuel source 17. Amaximum volume for reserve volume 302 characterizes the capacity of fuelsource 17 that reserve volume 302 can store. In one embodiment, reservevolume 302 includes a maximum volume between about 1 milliliter andabout 50 milliliters. A maximum volume between about 1 milliliter andabout 4 milliliters may be suitable for some portable electronicsapplications.

For the storage device 16 shown in FIG. 2C, reserve volume 302 comprisesthe volume of tube 109 between its upstream end where it interfaces withconnector 104 and its downstream end where it opens to the fuelprocessor 15. The inner diameter of tube 109 may be configured toprovide a particular volume maximum for reserve volume 302. In oneembodiment, tube 109 comprises plastic tubing with an outer diameterless than ¼ of an inch and a tube wall thickness between about 10 andabout 50 mils.

For the storage device 16 shown in FIG. 2B, reserve volume 302 comprisesa cavity within connector 140 that acts as a small reservoir for fuelsource 17 entering the electronics device 202. The cavity permits largermaximum volumes for reserve volume 302. The cavity may alternatively beconfigured downstream of connector 140 within the device 202 to receivefuel source 17 from line 109 after it passes through connector 140,e.g., closer to fuel processor 15. In this case, the maximum volume forreserve volume 302 includes contributions from both the cavity andtubing 109 traveling from the cavity to the fuel processor.

Reserve volume 302 may also comprise a bladder that conforms in size andshape to the volume of fuel source 17 contained therein. A rubber sac orfoldable bellows similar to those described above may be suitable. Inone embodiment, tube 109 collapses on itself when mating connector 140and connector 140 are separated. This seals tube 109 and prevent escapeof any fuel source 17 contained therein.

While this invention has been described in terms of several preferredembodiments, there are alterations, permutations, and equivalents thatfall within the scope of this invention which have been omitted forbrevity's sake. For example, although the present invention has beendescribed with respect to separate main controller 210 and fuel cellsystem controller 214, it is understood that these two functionalelements may be combined into a common controller. In addition, whilethe present invention has been described with respect to reformedmethanol fuel cell systems that include a fuel processor to convert thefuel source to hydrogen before receipt by the fuel cell, storage devicesdescribed herein are also useful for direct fuel source systems such asdirect methanol fuel cell systems. In a direct fuel source system, thestorage device provides the fuel source directly to the fuel cellwithout conversion to hydrogen by a separate fuel processor. While notdescribed in detail, such digital control of a mechanical system is wellknown to one of skill in the art. It is therefore intended that thescope of the invention should be determined with reference to theappended claims.

1. A hydrogen fuel source cartridge for storing a hydrogen fuel source,the cartridge comprising: a bladder that contains the hydrogen fuelsource; a housing having an internal cavity that includes the bladder; aconnector that interfaces with a mating connector to permit transfer ofthe fuel source between the bladder and a device that includes themating connector; a vent that allows air to enter and exit the internalcavity; and a hydrophobic and gas permeable filter configured tointercept air entering or exiting the housing through the vent.
 2. Thecartridge of claim 1 wherein the hydrophobic and gas permeable filter isconfigured to prevent the hydrogen fuel source from exiting the housingthough the vent.
 3. The cartridge of claim 1 wherein the hydrophobic andgas permeable filter is configured to prevent a foreign fluid orparticle from entering the housing though the vent.
 4. The cartridge ofclaim 1 further comprising a mechanical shield that spans the vent andprevents a foreign object from reaching the filter.
 5. The cartridge ofclaim 4 wherein the mechanical shield is arranged outside the filter anddisposed flush with or recessed from an outer surface of a wall in thehousing.
 6. The cartridge of claim 4 wherein the mechanical shieldincludes a flame suppressing material.
 7. The cartridge of claim 6wherein the mechanical shield includes a porous metal mesh.
 8. Thecartridge of claim 1 further comprising a flame suppressant disposed inthe vent.
 9. The cartridge of claim 1 wherein the hydrophobic and gaspermeable filter spans a cross section of the air vent.
 10. Thecartridge of claim 1 wherein the vent includes more than one hole in thehousing.
 11. The cartridge of claim 1 wherein the bladder conforms tothe volume of the hydrogen fuel source in the bladder.
 12. The cartridgeof claim 1 wherein a decrease in volume of the hydrogen fuel source inthe bladder draws air into the internal cavity and through the vent andfilter.
 12. The cartridge of claim 1 wherein an increase in volume ofthe hydrogen fuel source in the bladder pushes air out of the internalcavity and through the vent and filter.
 13. The cartridge of claim 1wherein the hydrogen fuel source includes methanol.
 14. A hydrogen fuelsource storage device for storing a hydrogen fuel source, the storagedevice comprising: a bladder that contains the hydrogen fuel source; ahousing having an internal cavity that includes the bladder; a connectorthat interfaces with a mating connector to permit transfer of the fuelsource between the bladder and a device that includes the matingconnector; a vent that allows air to enter and exit the internal cavity;and a hydrophobic and gas permeable filter configured to intercept airentering or exiting the housing through the vent; and a mechanicalshield that spans the vent and prevents a foreign object from reachingthe filter.
 15. The storage device of claim 14 wherein the hydrophobicand gas permeable filter is configured to prevent the hydrogen fuelsource from exiting the housing though the vent.
 16. The storage deviceof claim 14 wherein the mechanical shield is arranged outside the filterand disposed flush with or recessed from an outer surface of a wall inthe housing.
 17. The storage device of claim 14 wherein the mechanicalshield includes a flame suppressing material.
 18. The storage device ofclaim 14 wherein the bladder conforms to the volume of the hydrogen fuelsource in the bladder.
 19. The storage device of claim 14 wherein adecrease in volume of the hydrogen fuel source in the bladder draws airinto the internal cavity and through the vent, filter and mechanicalshield.
 20. A hydrogen fuel source storage device for storing a hydrogenfuel source, the storage device comprising: a bladder that contains thehydrogen fuel source; a housing having an internal cavity that includesthe bladder; a connector that interfaces with a mating connector topermit transfer of the fuel source between the bladder and a device thatincludes the mating connector; and a pressure relief configured to limitpressure of the hydrogen fuel source in the storage device.
 21. Thestorage device of claim 20 wherein the pressure relief is configured tolimit pressure in the bladder.
 22. The storage device of claim 21wherein the pressure relief includes a relief valve that releases thehydrogen fuel source from the bladder when pressure within the hydrogenfuel source reaches a threshold pressure.
 23. The storage device ofclaim 22 wherein the threshold pressure is less than or equal to theboiling point of the hydrogen fuel source.
 24. The storage device ofclaim 22 wherein the relief valve is included in the connector.
 25. Thestorage device of claim 20 further comprising a vent that allows air toenter and exit the internal cavity.
 26. The storage device of claim 20wherein the pressure relief is included in the housing.
 27. The storagedevice of claim 26 wherein the pressure relief is configured to releasethe hydrogen fuel source from the internal cavity.
 28. The storagedevice of claim 27 further comprising a hydrophobic and gas permeablefilter that is configured to intercept the hydrogen fuel source as itexits the internal cavity.
 29. The storage device of claim 28 whereinthe pressure relief is configured to release the hydrogen fuel sourcefrom the storage device when the hydrogen fuel source in the storagedevice reaches a threshold pressure.
 30. The storage device of claim 20wherein the pressure relief includes a spring.
 31. A hydrogen fuelsource storage device for storing a hydrogen fuel source, the storagedevice comprising: a bladder that contains the hydrogen fuel source; ahousing that provides mechanical protection for the bladder; a connectorthat interfaces with a mating connector to permit transfer of the fuelsource between the bladder and a device that includes the matingconnector; and a pressure relief valve configured to limit pressure inthe bladder by releasing hydrogen fuel source from the bladder whenpressure within the bladder reaches a threshold pressure.
 32. Thestorage device of claim 31 wherein the pressure relief includes a reliefvalve that releases the hydrogen fuel source from the bladder whenpressure within the bladder reaches a threshold pressure.
 33. Thestorage device of claim 32 wherein the threshold pressure is less thanor equal to the boiling point of the hydrogen fuel source.
 34. Thestorage device of claim 33 wherein the relief valve is included in theconnector.